I am moving to CO soon and I was told that my realtor that my MDX would need to be adjusted by the dealer for the change altitude. I live in NC, which is basicaly at sea level, and will be moving to CO which is above 6000 feet.

Is there anything that needs to be done to my X when I move? Will it run properly at higher altitude? I realize that the highest octane gas is only 91 in CO which might effect its performance, but will altitude cause it to run poorly?

Any thoughts would be greatly appreciated!

:4:

It should be self adjusting.....take advice from a realtor with caution..take that from someone who just passed the state exam.

Besides that, many of us a sea level are running 87 and 89 octane in our MDX's with no apparent problems.

 

My experience with Cars and Motorcycles (Porsche, Honda Gold Wing, several other and MDX) is that you can decrease your octane requirments by about 1-number for every 1000-1200 feet of Altitude. So 87 octane will be no problem in the Colorado Area. (And in reality, a lot of us have found 87 is no problem at Sea level either).

As far as getting anything re-adjusted, forgetaboutit--the MDX adjusts itself.

 

Nothing against realtors BUT --

would let your mechanic tell you how to price a home?!?

Every car with fuel injection (that is not a "fuelie Corvette" or British from the days before computers) has a means of adjusting the fuel delivery based on atmosphere. Sometimes it is just the O2 sensor in the exhaust, other systems also have a barometric sensor adding input to the computer.

Just drive baby!

(btw I know this may sound extreme, but since your realtor may be a "know-it-all-WRONG" I'd also double check the real estate side of your interactions with this person, I've been burned by folks who thing THEIR WAY is correct ionly to find out after the fact that the law was at odds the "know-it-all"...)

 

The MSO (manufacturer shipping order; like the title) supplied with my car said 'principal high-altitude use'. However, all modern FI systems self-adjust for altitude with the many sensors present.
The only thing I can think of is the 'default' parameters, since less fuel is required at higher altitudes (EPA at work, folks). Obviously, after a few hundred miles, the computer adjusts whatever parameters are appropriate for the conditions. I wouldn't worry about it. As a comment, EPA now forces manufacturers to put a very limited window of adjustment on ECMs, so modifying your exhaust and intake would no longer 'self adjust' properly, and probably would run too lean; you'd need the help of an aftermarket FI tuning device (an EGA is a must).
If you have a carbureted bike or car, it's a different story, but other than running extremely rich, no harm to the engine. However, doing the opposite is a real problem; you can blow an engine due to overly lean mixtures.

 

Re: Nothing against realtors BUT --

(btw I know this may sound extreme, but since your realtor may be a "know-it-all-WRONG" I'd also double check the real estate side of your interactions with this person, I've been burned by folks who thing THEIR WAY is correct ionly to find out after the fact that the law was at odds the "know-it-all"...)

There a lots of misinformed people. Some of those people are even realtors.

 

Re: Re: Altitude Adjustment

It should be self adjusting . . .

Just got back to sea level from a 6,000ft altitude, drove around there for four days w/o a problem. Maybe a longer period of time is needed before you would need to adjust. Check the Owner's Manual to see what it says, if anything, or call the dealer and see what they say. Then return and report :4:

 

Welcome to Colorado, soon i guess. i'm in colorado springs and there is NO adjustment needed for your MDX. The only thing you need when you get here is an emissions test at some auto place of your choice to get your plates. It'll cost you maybe 20-30 bucks.

 

I live in Colorado Springs as well (when I'm not a slave to the academic world...). I've found that there shouldn't be any problem, but you might notice that the car feels a little slower; it isn't a problem, but the engine can't get quite as much compression because the air is thinner.

Don't worry about it, though, it's not a problem!

If you want to know for sure, just ask at the dealer or wherever the first time you get an oil change after you get there... they'll know far better than I do!

:welcome: to Colorado!

 

Well the bad news, as far as power goes, is it will be down by about 25% at 7,500 feet. The good news is that the air is less dense, so you don't need as much HP to cruise at the same fixed speed. However, you will certainly not get the same 0-60 times as at sea level.
Oh boy, I can hardly wait to get the physicists in our group going on that one.

 

The MAP sensor doesnt care what altitude you're at. It tells the computer how much air is going into the engine and thats all that matters. And yes, you'll lose horsepower at higher altitudes.

Email me if you need real estate advice!

 

Thanks everyone for the advice. I did not think that in this day and age that there would need to be any adjustment, but I wanted to check with the "experts."

It was interesting seeing the reaction to realtors. My intent in mentioning that I heard that from a realtor was to give the reader some context. I do not think that my realtor's ignorance should reflect poorly on all realtors. My realtor might be great at helping people buy real estate, but be a lousy mechanic. I don't choose a realtor based on their knowledge of cars, just the local real estate market.

Anyway, thanks for the info. I knew that someone on this forum would be able to set me straight.

:4:

 

Well the bad news, as far as power goes, is it will be down by about 25% at 7,500 feet. The good news is that the air is less dense, so you don't need as much HP to cruise at the same fixed speed. However, you will certainly not get the same 0-60 times as at sea level.
Oh boy, I can hardly wait to get the physicists in our group going on that one.

That's the beauty of a turbo- it compensates for the less dense air to still give most of the HP. Saab was in a magazine comparison test once with some much more powerful BMWs and MBs up at altitude, and just blew them away.

 

It was interesting seeing the reaction to realtors. My intent in mentioning that I heard that from a realtor was to give the reader some context. I do not think that my realtor ignorance should reflect poorly on all realtors. My realtor might be great at helping people buy real estate, but be a lousy mechanic. I don't choose a realtor based on their knowledge of cars, just the local real estate market.

:4:

We were having fun at the expense of your realtor. But I am amazed a couple of agents I had encountered in the past were able to pass the state exam at all. Hardly an indictment on the profession overall, and the penalties for fraud are very severe. But even at that, a lot of illegal acitivity is still on-going sad to say. But most do not get away with it for very long, which only accentuates their stupidity.